lp_solve is a Mixed Integer Linear Programming (MILP) solver.  It is a
free (see LGPL for the GNU lesser general public license) linear
(integer) programming solver based on the revised simplex method and the
Branch-and-bound method for the integers.  It contains full source,
examples and manuals.  lp_solve solves pure linear, (mixed)
integer/binary, semi-continuous and special ordered sets (SOS) models.
